body {
  background-color: #333;
}
body .wrap {
  position: relative;
  margin: 0 auto;
  width: 570px;
  height: 700px;
  border: 1px solid #000;
  background-color: #c4c8cb;
}
body .wrap .mine {
  position: absolute;
  bottom: 15px;
  left: 50%;
  transform: translate(-50%, 0);
  width: 50px;
  height: 60px;
  background: url("../images/友军.png");
  background-size: 100%;
}
body .wrap .enemy {
  position: absolute;
  width: 30px;
  height: 21px;
  background: url("../images/敌军.png");
  background-size: 100%;
}
body .wrap .enemy:nth-of-type(2) {
  top: 50px;
  left: 440px;
}
body .wrap .pd {
  position: absolute;
  width: 12px;
  height: 23px;
  background: url("../images/子弹.png") no-repeat;
  background-size: 100% 100%;
}
